Table 2.

Olfaction function in patients with Parkinson's disease (PD) and controls.

Items	Patients with PD (n = 500)	Normal controls (n = 115)	p-value*
Threshold score (T)	4.75 (2.25–7.00)	7.50 (5.50–9.25)	0.001
Discrimination score (D)	7 (5–9)	10 (8–11)	<0.001
Identification score (I)	7 (5–9)	10 (9–12)	<0.001
TD score	12.50 (8.50–15.75)	16.75 (14.50–19.50)	<0.001
TI score	11.87 (7.75–15.50)	17.75 (15.50–20.75)	<0.001
DI score	14 (11–18)	20 (17–23)	<0.001
TDI score	19.50 (14.25–24.25)	28.25 (24.50–31.00)	<0.00

^*p-value was calculated after adjustment of age and educational years.